Hi,
CVI will use the ports that are available to the OS, the first thing is to make sure that the serial port is properly recognized in the OS as a regular serial port.
One way to test this is to use Hyperterminal and see if you can access the port there.
Also in CVI you can use the GetRS232Err() function to get more information on what is going on when you try to open the serial port.
Another thing to watch out for is the COM port number, some PCI to serial boards will install the serial ports in COM numbers higher than usual like COM8 and COM9 to avoid problmes with the built in serial ports. Just make sure that you reflec that in your CVI program.
I hope this helps.
Regards,
Juan Carlos
N.I.
